Systemic infectious diseases often lead to involvement of the central nervous system (CNS). Conversely, infectious diseases of the CNS frequently develop as part of systemic infections. This is particularly true for bacterial meningitis, encephalitis, and myelitis. Early recognition of these connections in clinical practice, along with the resulting specificities in therapy and diagnostics, is crucial for the prognosis of affected patients. This book addresses the most common diseases in this group from an interdisciplinary perspective: pneumococcal and meningococcal infections, endocarditis, septic focal encephalitis, spinal abscess, Lyme disease, tuberculosis, and Whipple's disease. A separate chapter is dedicated to cerebrospinal fluid diagnostics.